Efficient transistor structure

ABSTRACT

An integrated circuit comprises a first source, a first drain and a first gate that is arranged between the first source and the first drain. A first body is arranged in the first source. An edge of the first body is substantially aligned with the first gate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/691,237 filed on Oct. 22, 2003. The disclosures of the aboveapplication is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to transistor structures, and moreparticularly to transistor structures with reduced chip area.

BACKGROUND OF THE INVENTION

Integrated circuits or chips may include a large number ofinterconnected transistors. The transistors and other circuit elementsare interconnected in various ways to provide desired circuit functions.It is usually most efficient to fabricate multiple integrated circuitson a single wafer. After processing, the integrated circuits that arefabricated on the wafer are separated and then packaged. The wafer canaccommodate a fixed number of integrated circuits for a given integratedcircuit size. Reducing the size of individual transistors in theintegrated circuit may help to reduce the overall size of the integratedcircuit. This, in turn, allows an increased number of integratedcircuits or chips to be made on each wafer and reduces the cost of theintegrated circuits.

Referring now to FIGS. 1 and 2, an exemplary transistor 10 includes adrain 12, a gate 14, a source 16 and a body 18 or substrate tap. Forexample, the transistor 10 in FIG. 1 is an NMOS transistor. In somecircumstances, the body 18 is connected to the source 16 as shown inFIG. 2.

Referring now to FIG. 3, the body 18 includes a p⁺ region and mayinclude a contact tap 30. The source 16 includes an n⁺ region and mayinclude a contact tap 32. The drain 12 includes an n⁺ region and mayinclude a contact tap 34. Additional transistors may be fabricated onone or sides of the transistor 10 as indicated by “ . . . ” in FIG. 3.

Referring now to FIG. 4, the body 18 may be repeated between sources 16of adjacent transistors. The body 18 takes up valuable chip area andincreases the size of the transistor and the integrated circuit.Additional transistors can be arranged on one or more sides of thetransistor 10 as shown by “ . . . ” in FIG. 4.

SUMMARY OF THE INVENTION

An integrated circuit comprises a first source, a first drain, and afirst gate that is arranged between the first source and the firstdrain. A first body is arranged in the first source. An edge of thefirst body is substantially aligned with the first gate.

In other features, the first source and the first drain include n+regions and the first body includes a p+ region. The first body tapersas a distance between a midportion of the first body and the first gatedecreases. The first body has substantially at least one of a diamondshape, a circular shape, an elliptical shape, a hexagon shape, anoctagon shape and a football shape.

In other features, a second gate is arranged between the first sourceand the second drain. The first and second gates are connected.

An integrated circuit comprises a first source, a first drain, and afirst gate that is arranged between the first source and the firstdrain. A first body is arranged in the first source. A second gate isarranged between the first source and the second drain. The first bodyincludes a body contact tap. The first and second gates are arrangedfarther apart adjacent to the body contact tap than in areas that arenot adjacent to the body contact tap. An edge of the first body issubstantially aligned with the first gate.

In other features, the first body includes a body contact tap andwherein the first and second gates are arranged farther apart adjacentto the body contact tap than in areas that are not adjacent to the bodycontact tap. The first source includes a source contact tap. The firstand second gates are arranged farther apart adjacent to the sourcecontact tap than in areas that are not adjacent to the source contacttap. The first body includes a body contact tap. The first and secondgates are arranged farther apart adjacent to the body contact tap thanin areas that are not adjacent to the body contact tap. The firstsource, the first drain, and the second drain include n+ regions and thefirst body includes a p+ region. The first body tapers as a distancebetween a midportion of the first body and the first gate decreases. Thefirst body has substantially at least one of a diamond shape, a circularshape, an elliptical shape, a hexagon shape, an octagon shape and afootball shape.

An integrated circuit comprises a first source, a first drain, a firstgate that is arranged between the first source and the first drain, anda first body that is arranged in the first source. A second gate isarranged between the first source and the second drain. The first sourceincludes a source contact tap. The first and second gates are arrangedfarther apart adjacent to the source contact tap than in areas that arenot adjacent to the source contact tap. An edge of the first body issubstantially aligned with the first gate.

In other features, the first source includes a source contact tap. Thefirst and second gates are arranged farther apart adjacent to the sourcecontact tap than in areas that are not adjacent to the source contacttap. The first source, the first drain, and the second drain include n+regions and the first body includes a p+ region. The first body tapersas a distance between a midportion of the first body and the first gatedecreases. The first body has at least one of a diamond shape, acircular shape, an elliptical shape, a hexagon shape, an octagon shapeand a football shape. The first and second gates are connected.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating the preferred embodiment of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is an electrical symbol for a transistor with a drain, source,gate and body according to the prior art;

FIG. 2 is an electrical symbol for a transistor with a drain, source,gate and body, which is connected to the source according to the priorart;

FIG. 3 is an exemplary layout of the transistor of FIG. 2 according tothe prior art;

FIG. 4 is an exemplary layout of multiple transistors that are arrangedin a row according to the prior art;

FIG. 5A is a first exemplary layout of transistors including a body thatis arranged in the source;

FIG. 5B is a second exemplary layout of transistors including a bodyhaving edges that align with the gates in plan view;

FIG. 6 is a second exemplary layout of transistors including a body thatis arranged in the source;

FIG. 7 is a third exemplary layout of transistors including a body thatis arranged in the source;

FIG. 8 is a fourth exemplary layout of transistors including a body thatis arranged in the source; and

FIG. 9 is a fifth exemplary layout of transistors including a body thatis arranged in the source.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses. For purposes of clarity, the same referencenumbers will be used in the drawings to identify the same elements.Additional transistors can be arranged on one or more sides of theillustrated transistors that are shown in the FIGS. as indicated by “ .. . ” in the FIGS.

Referring now to FIGS. 5A and 5B, a transistor 50 according to thepresent invention is shown to include one or more sources 54 and one ormore drains 56. The sources 54 and the drains 56 include n⁺ regions.While an NMOS transistor is shown, skilled artisans will appreciate thatthe present invention also applies to other types of transistors such asPMOS transistors. Gates 58 are located between adjacent pairs of sources54 and drains 56. In one implementation, the gates 58 that are locatedon opposite sides of the sources 54 are connected together as shown at64. In other configurations, however, the gates 58 need not be connectedtogether.

A body 66 including a p⁺ region is arranged inside of and is surroundedby the source 54. The body 66 preferably has a shape that tapers as adistance between a midportion of the body 66 and adjacent gatesdecreases. The body 66 may touch or not touch the gates 58 in the planviews of FIGS. 5A and 5B. In other words, one or both edges of the body66 may be spaced from the gates 58 in plan view (as shown in FIG. 5A)and/or substantially aligns with the gates in plan view (as shown inFIG. 5B). By utilizing some of the area of the source 54 for the body66, the overall size of the transistor 50 is reduced as compared toconventional transistors. In the exemplary implementation that is shownin FIG. 5, the body 66 has a diamond shape.

Referring now to FIGS. 6 and 7, other exemplary shapes for the body 66are shown. In FIG. 6, the body 66 has a hexagon shape. In FIG. 7, thebody is generally football shaped. Skilled artisans will appreciate thatthere are a wide variety of other suitable shapes. For example, acircular body is shown in FIG. 8, which is described. Other suitableshapes include an ellipse, an octagon, etc.

Referring now to FIGS. 8 and 9, the gates 58 can be arranged such thatthey are closer together when there are no contact taps and furtherapart when there are contact taps. In FIG. 8, a source contact tap 70,which is not located in the body 66, is located in a region where theadjacent gates 58 are located farther apart. In FIG. 9, a body contacttap 80, which is located in the body 66, is located in the source 54where the adjacent gates 58 are located farther apart.

Those skilled in the art can now appreciate from the foregoingdescription that the broad teachings of the present invention can beimplemented in a variety of forms. Therefore, while this invention hasbeen described in connection with particular examples thereof, the truescope of the invention should not be so limited since othermodifications will become apparent to the skilled practitioner upon astudy of the drawings, the specification and the following claims.

1. An integrated circuit comprising: a first source; a first drain; afirst gate that is arranged between said first source and said firstdrain; and a first body that is arranged in said first source, whereinan edge of said first body is substantially aligned with said firstgate.
 2. The integrated circuit of claim 1 wherein said first source andsaid first drain include n⁺ regions and said first body includes a p⁺region.
 3. The integrated circuit of claim 1 wherein said first bodytapers as a distance between a midportion of said first body and saidfirst gate decreases.
 4. The integrated circuit of claim 1 wherein saidfirst body has substantially at least one of a diamond shape, a circularshape, an elliptical shape, a hexagon shape, an octagon shape and afootball shape.
 5. The integrated circuit of claim 3 further comprising:a second drain; and a second gate that is arranged between said firstsource and said second drain.
 6. The integrated circuit of claim 7wherein said first and second gates are connected.
 7. An integratedcircuit comprising: a first source; a first drain; a first gate that isarranged between said first source and said first drain; a first bodythat is arranged in said first source; a second drain; and a second gatethat is arranged between said first source and said second drain,wherein said first body includes a body contact tap and wherein saidfirst and second gates are arranged farther apart adjacent to said bodycontact tap than in areas that are not adjacent to said body contacttap, and wherein an edge of said first body is substantially alignedwith said first gate.
 8. The integrated circuit of claim 7 wherein saidfirst body includes a body contact tap and wherein said first and secondgates are arranged farther apart adjacent to said body contact tap thanin areas that are not adjacent to said body contact tap.
 9. Theintegrated circuit of claim 7 wherein said first source includes asource contact tap and wherein said first and second gates are arrangedfarther apart adjacent to said source contact tap than in areas that arenot adjacent to said source contact tap.
 10. The integrated circuit ofclaim 7 wherein said first body includes a body contact tap and whereinsaid first and second gates are arranged farther apart adjacent to saidbody contact tap than in areas that are not adjacent to said bodycontact tap.
 12. The integrated circuit of claim 7 wherein said firstsource, said first drain, and said second drain include n⁺ regions andsaid first body includes a p⁺ region.
 13. The integrated circuit ofclaim 7 wherein said first body tapers as a distance between amidportion of said first body and said first gate decreases.
 14. Theintegrated circuit of claim 7 wherein said first body has substantiallyat least one of a diamond shape, a circular shape, an elliptical shape,a hexagon shape, an octagon shape and a football shape.
 15. Anintegrated circuit comprising: a first source; a first drain; a firstgate that is arranged between said first source and said first drain; afirst body that is arranged in said first source; a second drain; and asecond gate that is arranged between said first source and said seconddrain, wherein said first source includes a source contact tap andwherein said first and second gates are arranged farther apart adjacentto said source contact tap than in areas that are not adjacent to saidsource contact tap, and wherein an edge of said first body issubstantially aligned with said first gate.
 16. The integrated circuitof claim 15 wherein said first source includes a source contact tap andwherein said first and second gates are arranged farther apart adjacentto said source contact tap than in areas that are not adjacent to saidsource contact tap.
 17. The integrated circuit of claim 15 wherein saidfirst source, said first drain, and said second drain include n⁺ regionsand said first body includes a p⁺ region.
 18. The integrated circuit ofclaim 15 wherein said first body tapers as a distance between amidportion of said first body and said first gate decreases.
 19. Theintegrated circuit of claim 15 wherein said first body has at least oneof a diamond shape, a circular shape, an elliptical shape, a hexagonshape, an octagon shape and a football shape.
 20. The integrated circuitof claim 15 wherein said first and second gates are connected.